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Earth Science

'Sea Nomads' Are First Known Humans Genetically Adapted To Diving (nationalgeographic.com) 111

schwit1 shares a report from National Geographic: Most people can hold their breath underwater for a few seconds, some for a few minutes. But a group of people called the Bajau takes free diving to the extreme, staying underwater for as long as 13 minutes at depths of around 200 feet. These nomadic people live in waters winding through the Philippines, Malaysia, and Indonesia, where they dive to hunt for fish or search for natural elements that can be used in crafts. Now, a study in the journal Cell offers the first clues that a DNA mutation for larger spleens gives the Bajau a genetic advantage for life in the deep.
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'Sea Nomads' Are First Known Humans Genetically Adapted To Diving

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  • by fred911 ( 83970 ) on Friday April 20, 2018 @10:23PM (#56475785)

    Hazen Audel dove with these people on season 3 episode 1 called "Trial by Ocean". And, they're not really Nomads. Pretty interesting watch.

  • I think I read this about 30 years ago. I think there were stranded there from a cruise ship.
  • by JoshuaZ ( 1134087 ) on Friday April 20, 2018 @10:48PM (#56475875) Homepage
    From TFA: When you go hold your breath and are surrounded by water you have a bunch of physiological responses that happen automatically. One major one is that your spleen contracts delivering more red blood cells to your arteries. Since they have larger spleens, there's a larger reservoir of red blood cells ready to get pushed out when necessary.
    • by skids ( 119237 ) on Saturday April 21, 2018 @12:29AM (#56476207) Homepage

      I was about to say "I must have a really small spleen these days considering how much I hate holding my breath."

      But I guess that reasoning is void, because I haven't been fully immersed in water in decades... so...

    • Which does not really make sense, as the red blood cells can not pick up magically some oxygen that is not there.
      You are limited by the oxygen you breath in when starting to dive ... no matter how many red blood cells later get released by the spleen.

      • I'm sure that the five minutes of thought you've put in to this have found a critical flaw that the scientists didn't anticipate at all in their calculations. I suggest you look at for example https://link.springer.com/article/10.2165/00007256-200232060-00002 [springer.com] which discusses in more detail some of the underlying biology for why putting in more red blood cells has an effect of the type they are predicting.
  • The world record holder for underwater breath-holding is German. I guess they have these spleens too. Who knew?
    • The world record holder for underwater breath-holding is German. I guess they have these spleens too. Who knew?

      He did it by breathing pure oxygen for 20 minutes before his attempt.

      The longest known breath-hold without supplemental O2 is about 11 minutes. That was someone passively holding their breath. Someone actively consuming oxygen by swimming deep would have less time. So the 13 minutes claimed in TFA is likely BS.

      • The same effect (to a lesser degree) can be achieved by hyperventilating for a while before attempting to hold your breath or swim under water.

        • Re:Germans (Score:4, Informative)

          by Anonymous Coward on Saturday April 21, 2018 @04:25AM (#56476683)

          Hyperventilating is dangerous and is specifically advised against during freediving courses. The reason is twofold.

          First, our urge to breathe is controlled by high CO2, not low O2, and hyperventilation removes CO2 from the blood without adding much O2 (it's already at 97+% of the possible maximum by default). Three deep breaths is the golden middle that fully replaces CO2 with O2 in lungs without affecting the blood composition too much. So those who hyperventilate do not, actually, get more time until a blackout, they just get "more comfortable" time, and "more comfortable" to a not really predictable degree. I.e. useless to really say "enough" to oneself.

          Second, red blood cells are not willing to give away the oxygen they are carrying if there is not enough CO2.

      • He did it by breathing pure oxygen for 20 minutes before his attempt.
        Pure oxygen would kill you in a matter of seconds, unless you use a very low pressure, like something like 100mB, I wonder if that had any effect on diving.

        As a child I could hold breath for more than 5 minutes (under water, but not swimming), my mother did not allow me for longer times, she was to scared. Active diving I can about 3 minutes to a depth of about 10 meters. But I don't practice it ... (I mean, no real training)

        Combat divers

        • Pure oxygen would kill you in a matter of seconds

          Pure oxygen at STP will take hours to do significant permanent damage to an otherwise healthy person. Your claim isn't even reasonable.

          • At atmosphere pressure pure oxygen is deadly, you should not have deleted the rest of my sentence.

          • At pressure, pure oxygen is toxic, which is likely what he was referring to. Scuba divers regularly use pure oxygen to help offgas CO2 during decompression, however, this is only allowed/safe at https://en.wikipedia.org/wiki/...
    • Re:Germans (Score:5, Insightful)

      by Jodka ( 520060 ) on Friday April 20, 2018 @11:06PM (#56475929)

      The world record holder for underwater breath-holding is German.

      Maybe the Bajau are under-represented entrants in the contest.

      • Relative to the population? There's 80M Germans, after all. Large populations tend to generate more extremes if you have a Top-N table where N is a fixed small integer.
        • by torkus ( 1133985 )

          Relative to the population of people who frequently hold their breath for extended periods of time. At least define your terms to match the discussion. This isn't something that the population as a whole is tested for.

    • No they simply use science and technology to achieve what the Bajau have naturally evolved to do. The german achieved this in a highly relaxed and controlled environment with carefully controlled water temp and first flooding his lungs with pure oxygen to significantly increase the amount he could stay underwater (the pure oxygen alone is estimated to have added at least 10 mins to the time). The Bajau do theirs on normal air, in the ocean while swimming not relaxing.
      • Of course none of that has been documented. There have been documented cases of people lasting 12 minutes without "science and technology". So I am calling BS on this "spleen" explanation.
        • I'm not sure you know what "documented" means. When a scientist goes out and does a study, get's it reviewed, and publishes it, that's documentation. The article we're talking about here is the current best documentation and explanation we have of why some people can hold their breath longer than others.

          • by torkus ( 1133985 )

            If the Guinness Book of World Records doesn't officiate something then it doesn't count!

            If people do something extraordinary and it doesn't hit social media and trend, then it never really happened.

            Don't you know these basic rules of society??

        • by dryeo ( 100693 )

          The odd individual in other populations may also have an extra large spleen.
          At that, often these types of mutations are spread through the population and then in some populations, gets selected for.

        • So a study by scientists and published in a journal no longer qualifies as documented?
  • not "First Known Humans Genetically Adapted to xx". And it's a direct copy of the National Geographic headline. I guess they too have no editors.
  • Bajau takes free diving to the extreme, staying underwater for as long as 13 minutes at depths of around 200 feet.

    Kevin Costner [imdb.com] scoffs at the Bajau pathetic diving abilities.

  • and not heavy training from a young age?
    • by quenda ( 644621 ) on Saturday April 21, 2018 @01:57AM (#56476389)

      and not heavy training from a young age?

      RTF Study summary:

      Using a comparative genomic study, we show that natural selection on genetic variants in the PDE10A gene have increased spleen size in the Bajau, providing them with a larger reservoir of oxygenated red blood cells. We also find evidence of strong selection specific to the Bajau on BDKRB2, a gene affecting the human diving reflex.

      So yes, there is a genetic basis for part of the different abilities between races, and we are starting to find it.
      I wonder if National Geographic will one day be apologising for how racist they were to print this?

      https://www.nationalgeographic... [nationalgeographic.com]

      • I wonder if National Geographic will one day be apologising for how racist they were to print this?

        As long as the comment refers only to a minority, that's fine, they won't be sued, however it's true (or false).

      • Re: (Score:2, Troll)

        by fafalone ( 633739 )
        It's not racist because genetics stops at the neck. Claiming that somehow genes might influence how brains work, now that's just racist. And sexist. Any science that says any group might have a genetic variation resulting in a cognitive difference is racist and sexist, and any evidence saying that is just white male supremacy. But of course genetics influences physical differences.

        (This stupidity is really what some people think, even some people here)
        • by Anonymous Coward

          No, the reason people that makes claims like that are called racist is because the studies they cite as proof are used with IQ-tests that where specifically made to prove that certain races are subhuman and didn't take education level into consideration.
          If you take the smartest child and don't teach it how to read then it won't score very well on an IQ-test.
          If your IQ-test contains questions containing pennies and nickles then people using a different monetary system will have a larger problem with them.

          IQ-

          • If you just make the claim that genetics may have an impact on how brains work without bringing up pseudoscience to "prove" that certain races are inferior

            So, two groups of people can have differences in their brains, but they will always be equally good at performing arbitrary mental tasks ?

          • IQ tests are an extremely small part of the picture. And you clearly are just repeating sjw propaganda and are unfamiliar with the actual research you're criticizing, or IQ tests in general let alone group comparisons. IQ tests weren't made to prove some people are subhuman, that's ridiculous (all tests show differences). You know the evil racist white men don't even score the highest right? And if the problems you described were significant, the test wouldn't have the same predictive power. And no matter w
            • by dryeo ( 100693 )

              Actually IQ tests were originally created to show that some people (East Europeans at the time) were sub-human. They originally had questions such as "who won the world series" and "what is Smith Wesson known for manufacturing" (spelling may be incorrect).
              A hundred odd years ago there was a movement to limit immigration to keep the Slav's out.

              Anyways, even if certain populations are lower in intelligence on average, it does not mean that all members of that population are lower in intelligence.

              • by quenda ( 644621 )

                Anyways, even if certain populations are lower in intelligence on average, it does not mean that all members of that population are lower in intelligence.

                Wow, thanks for that mathematical insight. You deserve a Fields medal.

                • by dryeo ( 100693 )

                  Seems I have more mathematical insight then a lot of posters here.

                  • by quenda ( 644621 )

                    Seems I have more mathematical insight then a lot of posters here.

                    You should give people more credit. We all see the obvious.
                    It sounds like you are talking about old immigration screening tests in the United States? Clearly, and by design, these were not cognitive tests.
                    My own country used similar "language" tests on immigrants they did not desire, but what has that got to do with anything?

                    One of the early uses of cognitive (IQ) tests in the US was to identify talented kids from minority backgrounds, and give them educational opportunities they would not previously have

              • Why do you lie? Intelligence testing originated in France.
      • by Anonymous Coward

        The concept was rejected in the 1920 by everyone except the radical nationalists (including the Nazis and, to this day, the USA), because the differences were just way too small to warrant differentiating!

        The differences inside "races" were often bigger than between "races"!

        And genetically, it gets even worse. The concept is utterly useless, and only exists to help losers with an inferiority complex declare themselves "special", based on superficial and mostly exterior differences. Clinging to a small genti

        • So you claim there's no benefit to finding the underlying causes of Tay-Sachs disease or sickle cell disease.
  • a lead to my theory... follow it or not.
  • Another example of genetic adaptations that was discovered earlier are the Tibetans, whose homeland is a vast highland with average altitude of about 4,000 meters (13,000 feet). Having superior oxygen intake and resistance to effects like Acute Mountain Sickness helped the Tibetans to populate and defend their highland territory over the millenia. The few foreign expeditions that ever made it to their capital Lhasa were either allowed to enter (e.g. Mongols who ended up adopting Buddhism from Tibet) or didn

    • Another example of genetic adaptations that was discovered earlier are the Tibetans, whose homeland is a vast highland with average altitude of about 4,000 meters (13,000 feet). Having superior oxygen intake and resistance to effects like Acute Mountain Sickness helped the Tibetans to populate and defend their highland territory over the millenia. The few foreign expeditions that ever made it to their capital Lhasa were either allowed to enter (e.g. Mongols who ended up adopting Buddhism from Tibet) or didn't linger for too long.

      You don't need genetic adaptation for that. Just spending a year at high altitude will cause your body to adapt, your blood actually changes. If invaders would have found some other mountains to train in, they might have successfully invaded.

  • This is racism! All right-thinking people know that everyone born a blank slate and good at everything and race is just a social construct.
  • Every human is capable to train for 2 or more minutes diving.

    I did not dive for 30 years but when I was in Thailand 2 years ago I dived like 3 or 4 minutes without any recent training.

    Does not mean there is no such gene ...

    • Every? My nephew has one lung. I'm sure there's plenty of fucking people who can't do two minutes. Do you just say shit just to read what you said?
      • You want to say he has half a lung?

        What has that to do with my argument? I'm pretty sure if he practices a little bit, he can hold his breath for two minutes.

        Hint: nitpicking does not win an argument.

  • I can hold my breath for ten minutes.

    https://www.youtube.com/watch?... [youtube.com]

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